Reassessment of the first ionization potentials of copper, silver, and gold (original) (raw)
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Spectroscopy of highly ionised copper and nickel
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1987
Beam-foil techniques have been used to study the spectra of highly ionised copper and nickel. These spectral studies have led to the identification of a number of new lines. Identifications are given for a number of transitions in Cu XV.
Ionization Model for Nickel-Like Gold
Le Journal de Physique Colloques, 1986
Resum6-A l'aide d'un modble trbs simplifie, mais qui permet une bonne interpretation des spectres experimentaux obtenus sur l'or, nous mettons en dvidence l'importance des transitions souvent consid6rees comme faiblement importantes : cascades et transitions "horizontales".
Electron impact single ionization of copper
Pramana, 2000
Electron impact single ionization cross sections of copper have been calculated in the binary encounter approximation using accurate expression for ¡ as given by Vriens and Hartree-Fock momentum distribution for the target electron. The BEA calculation based on the usual procedure does not show satisfactory agreement with experiment in this case but a striking modification is found to be successful in explaining the experimental observations. The discrepancy is linked with the ionization of the ¿ ½¼ electrons and probably effective single ionization does not take place from ¿ shell of copper leading to smaller values of experimental cross sections.
Canadian Journal of Physics, 1982
Single-configuration relativistic Hartree-Fock values of thc first ionization potentials for Cu through Kr7+, Ag through 1°+, and Au through pb3+ are computed in "frozcn" and "relaxed core" approximations with and without allowance for core polarization. Effects of thc polarization of thc atomic core by the valence clectron are includcd by introducing a polarization potential in the one-electron Hamiltonian of the valence electron. Thc core polarization potential dcpends on two pararnetcrs, thc static dipole polarizability of the core a and the cut-off radius r~, , which are chosen independently of thc ionization potential data. It is demonstrated that by including the corc polarization potential with a and r,, parameters which arc sinlply chosen instcad of being empirically fittcd, it is still possiblc to account, on thc average, for at least 70% of thc discrepancy bctwccn the single-configuration relativistic Hartrec-Fock ionization potentials and thc expcrimcnt, a discrepancy usually ascribed to the contribution of valcnce-core clectron correlations, and to bring the theoretical ionization potentials to an averagc agreement with experiment of around 1%. The core polarization contribution to ionization potentials is also compared with the contribution of the relaxation of thc core and with relativistic effccts. An estirnatc of55.0 * 0. I eV is suggcstcd as thc bcst value of the ionization potential of Sb4+.
The influence of cupric ions on shape of potentiodynamic curves obtained on 18 K gold
Journal of Mining and Metallurgy Section B-metallurgy, 2002
The shape of potentiodynamic curves depends mainly on the composition of investigated alloys, but also on the electrolyte used in experiments. In this work investigation were performed for pure gold, and pure silver and copper as alloying metals, then for binary alloys Au-Ag and Au-Cu containing gold as in 18 k gold (i.e. 75 % Au) and Ag-Cu with mass ratio 1:1 and, finally, for three component 18 k gold. It was established a catalytic effect of cupric ions present in electrolyte on oxidation of gold and 18 k gold alloys.
ION BEAM ANALYSIS OF COPPER AND COPPER ALLOY COINS
Archaeomelry 30 (1988) 187-197.
Different analytical methods are now available for researchers working on copper or copper alloy coins and objects. A comparison of three non-destructive ion beam techniques is presented: particle-induced X-ray emission (PIXE) using a van de Graaff accelerator, proton activation analysis (PAA) and fast neutron activation analysis (FNAA) using a cyclotron. In order to verify the accuracy and the precision of these three methods our experiment was first carried out on brass and bronze industrial standards and afterwards on five coins described in table 1, with the following composition: one of copper, two of orichalcum and two of lead-bronze.
The NIST compilation of ionization potentials revisited (I): From He-like to Xe-like ions
Canadian Journal of Physics, 2017
The National Institute of Standards and Technology (NIST) database on ionization potentials for neutral atoms and ions is examined. For each isoelectronic sequence, we construct a regularized perturbative series based on the large-Z (heavy cations) and Z ≈ N – 1 (singly charged anion) behaviors. Comparison of the NIST data with this series allows the identification of problematic values in the reported data.
Electron impact ionization/dissociation of size selected gold cluster cations
Journal of Electron Spectroscopy and Related Phenomena, 2000
Singly charged gold clusters, Au in the size range n512 to 72 have been captured and stored in a Penning trap, size n selected and subjected to an electron beam. This interaction leads to further ionization as well as dissociation. The resulting abundance spectra of doubly and triply charged clusters show (a) a lower size limit for the production of multiply charged clusters from an ensemble of hot precursors, which can be understood in terms of the respective decay pathways, (b) an odd / even alternation of singly and doubly charged clusters in the size range below n530, which inverses sign with change of charge state, and (c) magic numbers, i.e. prominent signals for particular cluster sizes, which can be identified as closed electronic shells. In contrast to similar experiments on silver clusters and in spite of the well-known ligand-stabilized species, there is no indication of a particularly stable charge-state-independent cluster size of n555.
The NIST compilation of ionization potentials revisited: From He-like to Xe-like ions
2016
for neutral atoms and ions is examined. For each isoelectronic sequence, we construct a regularized perturbative series that exactly matches the large-Z and Z ≈ N − 1 regions. Comparison of the NIST data with this series allows the identification of problematic data values. PACS numbers: 32.30.-r, 32.10.Hq, 31.15.-p Physics is indeed a mature science. Large amounts of data, of very different kinds, have been accumulated along decades. Sometimes, a fresh look at these com-pilations, on the basis of simple-physically meaningful-models, leads to a qualitative understanding of the data. In a previous paper1, we show that the NIST data on ionization potentials of atomic ions 2 can be accomodated along a single universal curve, based on Thomas-Fermi scaling features. In the present work, we go a step further and develop a simple model allowing the identification of problematic